Validation of the NFL-225 test for predicting 1-RM bench press performance in college football players

Abstract

Background. The purpose of this study was to evaluate the accuracy of repetitions-to-fatigue (RTF) using an absolute load of 102.3 kg (225 lbs) to estimate one-repetition maximum (1-RM) bench press performance in college football players using various prediction equations. Methods. Experimental design: a prospective study on the association between muscular endurance and muscular strength. Participants: 260 players from NCAA Division IA (n=43), IAA (n=63), II (n=129), and red-shirts (n=25) were evaluated at the conclusion of a minimum of eight weeks of heavy-resistance training during the off-season. Measures: all subjects performed a 1-RM bench press and RTF using an absolute load of 102.3 kg. Results. The Mayhew et al. NFL-225 equation nonsignificantly overestimated 1-RM from RTF by 0.5 kg, while the Chapman et al. NFL-225 equation significantly underpredicted by 3.2 kg, although both equations were comparable in the number of players predicted within ±4.5 kg of actual 1-RM (52% vs 51%, respectively). Only two of nine RTF equations currently in use produced predicted 1-RM values that were not significantly different from actual 1-RM performance. Conclusions. Specific NFL-225 equations are more accurate in estimating 1-RM bench press from absolute muscle endurance in college football players than previous published RTF equations. The accuracy of prediction decreases at higher repetitions.